From 2418da7d4f67f33bd8a0408356ee87b71acb9e71 Mon Sep 17 00:00:00 2001
From: Yosuke Ota <otameshiyo23@gmail.com>
Date: Thu, 26 Dec 2019 09:46:48 +0900
Subject: [PATCH] Fixed an issue that caused an error when extra commas were
 included in `require-prop-type-constructor` (#963)

---
 lib/rules/require-prop-type-constructor.js    |  2 +-
 lib/utils/index.js                            |  1 +
 .../rules/require-prop-type-constructor.js    | 72 +++++++++++++++++++
 3 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/lib/rules/require-prop-type-constructor.js b/lib/rules/require-prop-type-constructor.js
index d6c00e257..edde36f49 100644
--- a/lib/rules/require-prop-type-constructor.js
+++ b/lib/rules/require-prop-type-constructor.js
@@ -58,7 +58,7 @@ module.exports = {
         })
       } else if (node.type === 'ArrayExpression') {
         node.elements
-          .filter(prop => isForbiddenType(prop))
+          .filter(prop => prop && isForbiddenType(prop))
           .forEach(prop => context.report({
             node: prop,
             message,
diff --git a/lib/utils/index.js b/lib/utils/index.js
index d6c9221a1..5e32fa9bf 100644
--- a/lib/utils/index.js
+++ b/lib/utils/index.js
@@ -453,6 +453,7 @@ module.exports = {
         })
     } else {
       props = propsNode.value.elements
+        .filter(prop => prop)
         .map(prop => {
           const key = prop.type === 'Literal' && typeof prop.value === 'string' ? prop : null
           return { key, value: null, node: prop, propName: key != null ? prop.value : null }
diff --git a/tests/lib/rules/require-prop-type-constructor.js b/tests/lib/rules/require-prop-type-constructor.js
index 1e3ca6d94..70fc35e8e 100644
--- a/tests/lib/rules/require-prop-type-constructor.js
+++ b/tests/lib/rules/require-prop-type-constructor.js
@@ -44,6 +44,56 @@ ruleTester.run('require-prop-type-constructor', rule, {
           }
         }
       `
+    },
+    {
+      filename: 'ExtraCommas.vue',
+      code: `
+        export default {
+          props: {
+            name: [String,,]
+          }
+        }
+      `
+    },
+    {
+      filename: 'ExtraCommas.vue',
+      code: `
+        export default {
+          props: {
+            name: {
+              type: [String,,]
+            }
+          }
+        }
+      `
+    },
+    {
+      filename: 'ExtraCommas.vue',
+      code: `
+        export default {
+          props: {
+            name: [String,,Number]
+          }
+        }
+      `
+    },
+    {
+      filename: 'ExtraCommas.vue',
+      code: `
+        export default {
+          props: {
+            name: [,,Number]
+          }
+        }
+      `
+    },
+    {
+      filename: 'ExtraCommas.vue',
+      code: `
+        export default {
+          props: ['name',,,]
+        }
+      `
     }
   ],
 
@@ -165,6 +215,28 @@ ruleTester.run('require-prop-type-constructor', rule, {
         line: 5
       }],
       parser: require.resolve('@typescript-eslint/parser')
+    },
+    {
+      filename: 'ExtraCommas.vue',
+      code: `
+      export default {
+        props: {
+          name: ['String',,]
+        }
+      }
+      `,
+      output: `
+      export default {
+        props: {
+          name: [String,,]
+        }
+      }
+      `,
+      errors: [{
+        message: 'The "name" property should be a constructor.',
+        line: 4
+      }],
+      parser: require.resolve('@typescript-eslint/parser')
     }
   ]
 })